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red 2k @120 fps, or 16mm @ 150 fps


Oliver Ojeil

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Hey, I have a pop promo coming up, there will be a lot of rotoscoping and many elements added in post to the live footage.

The plan is to shoot on RED @ 4K with zeiss ultraprimes, and an Angenieux HR, I need to shoot parts of the promo at high speed, My DP is telling me against shooting the highspeeds @ 2k on the RED, according to him the image quality at 2k is lower than 4k downconverted to 2k, and we will need to rent another set of 16mm primes, as the ultraprimes have lower resolution on the 2k sensor size.

Has anyone compared the following situations?

 

red 4k, Zeiss 50mm HS prime (35mm film lens)

red 2k, Zeiss 25mm HS prime (16mm film lens)

 

This will keep the same field of view and to a point the same depth of field.

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Your DP is right about downconversion looking better than native 2K, and you would want to get the proper lenses for the smaller format. But Red 2K would match with the Red 4K material far better than 16mm would. Grain and color space would be quite different. For rotoscoping and composites, staying all digital will make the post a lot easier, because you don't have the mechanical registration problem. For high speed, the right answer may be the Phantom.

 

 

 

-- J.S.

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Ditto on everything John said. The experience I've had has been that RED's 2K is always comparably softer to their 4K, and 16mm is somewhat hard to match up to RED's stuff for a miriad of reasons...generally speaking.

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Hey, I have a pop promo coming up, there will be a lot of rotoscoping and many elements added in post to the live footage.

The plan is to shoot on RED @ 4K with zeiss ultraprimes, and an Angenieux HR, I need to shoot parts of the promo at high speed, My DP is telling me against shooting the highspeeds @ 2k on the RED, according to him the image quality at 2k is lower than 4k downconverted to 2k, and we will need to rent another set of 16mm primes, as the ultraprimes have lower resolution on the 2k sensor size.

Has anyone compared the following situations?

 

red 4k, Zeiss 50mm HS prime (35mm film lens)

red 2k, Zeiss 25mm HS prime (16mm film lens)

 

This will keep the same field of view and to a point the same depth of field.

 

 

There's no doubt that 2K on the RED is very very average. However, given you have lot's of roto work, I'd say RED. 16mm Image stability will make it a lot harder and it will be easier to match the red 4K shots. Just expect a BIG difference.

 

jb

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  • 2 weeks later...
Is the 2K from RED comparable in quality with the 1080 output from the Sony Cinealta HD cams? (900, 950 etc). I'm talking only about windowed 2K, not 4K downsized in post to 2K.

 

Thanks.

 

Don't know much about windowed 2K on Red. However, a comment on 4K->2K vis direct 2K:

 

In signal processing terms, one can have a steeper low pass filter (sharper transition from pass to stop band) when using a light low pass filter, then oversampling (not upsampling), and then downsampling, as opposed to the application of a low pass filter directly. Therefore, Red should have an advantage when going from 4K->2K to cameras that offer direct 2K or close to 2K resolution (such as HD cameras).

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Hey, I have a pop promo coming up, there will be a lot of rotoscoping and many elements added in post to the live footage.

The plan is to shoot on RED @ 4K with zeiss ultraprimes, and an Angenieux HR, I need to shoot parts of the promo at high speed, My DP is telling me against shooting the highspeeds @ 2k on the RED, according to him the image quality at 2k is lower than 4k downconverted to 2k, and we will need to rent another set of 16mm primes, as the ultraprimes have lower resolution on the 2k sensor size.

Has anyone compared the following situations?

 

red 4k, Zeiss 50mm HS prime (35mm film lens)

red 2k, Zeiss 25mm HS prime (16mm film lens)

 

This will keep the same field of view and to a point the same depth of field.

 

I don't know what your DP is smoking (or why other posters thought you were going to shoot 16mm film to match the RED 4k), but Ultra Primes should NOT have a lower res at 2k than 16mm primes on the RED at 2k. In fact, the Ultra Primes should be much sharper since you will be using the sweet part of the glass instead of the full glass element on the 16mm primes. However, he is correct that 2k will be softer (and nosier) than the 4k down converted to 2k. My suggestion is if you don't need to shoot over 60fps, then shoot 3k as it looks very nice. You are also correct in understanding that while your DOF hasn't changed when going to 2k, your FOV has and so when you try to match your FOV, your DOF will change and you need to switch lenses accordingly.

 

Matthew

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Is the 2K from RED comparable in quality with the 1080 output from the Sony Cinealta HD cams? (900, 950 etc). I'm talking only about windowed 2K, not 4K downsized in post to 2K.

 

Thanks.

 

A lot of Red 2K (windowed) overcranked footage I have seen looks quite soft, especially the low-light stuff. The best bet seems to be 3K overcranking on Red One. There is a lens conversion factor to keep in mind relative to 4K, however.

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A lot of Red 2K (windowed) overcranked footage I have seen looks quite soft, especially the low-light stuff. The best bet seems to be 3K overcranking on Red One. There is a lens conversion factor to keep in mind relative to 4K, however.

 

RED shot @ 2k in less than extremely optimal situations, looks a lot worse than anything shot @ 3k or 4k. Which gives you a "good" part of the RED topping off @ 60 fps.

 

2k is very useable in a lot of situations, but if you're going for cinematic relase, 3k is the way to go.

 

Gunleik

Edited by Gunleik Groven
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RED shot @ 2k in less than extremely optimal situations, looks a lot worse than anything shot @ 3k or 4k. Which gives you a "good" part of the RED topping off @ 60 fps.

 

2k is very useable in a lot of situations, but if you're going for cinematic relase, 3k is the way to go.

 

Gunleik

 

Hi,

 

I have been dissapointed by 2k Red, 3K & 4k looks very good.

 

Stephen

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Hi,

 

I have been dissapointed by 2k Red, 3K & 4k looks very good.

 

Stephen

 

Hey Stephen,

 

Now that we're in the post process and am scrubbing through the rushes as I type, I second your comment, and am even more disappointed by RED in low light situations.

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Hi Oliver,

 

Were you using tungsten light?

 

Stephen

 

 

Hey Stephen,

 

We stayed as far from tungsten lighting as possible, especially that this was our first job with the camera.

 

Will post some screengrabs as we get to the grading process.

 

Regards

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  • 1 month later...

It's important to note that 2K Red footage shot with lenses wider than 25mm and wide open are soft if the subject is more than 15 feet from the camera. It simply cannot resolve focus, which is a big issue when getting wide shots with the red. As you stop down to 5.6 or 8 or so the image gets much sharper. A 25 mm focal length at 2K becomes a 50mm, so shooting big wide shots with a far off focus at 2K in low light is absolutely impossible in my experience. Shoot 3K at 60 frames, with a slim shutter to minimize motion blur and use AE plugin Twixtor to extrapolate back out to 120fps.

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Is the 2K from RED comparable in quality with the 1080 output from the Sony Cinealta HD cams? (900, 950 etc).

 

Probably not quite. You're probably looking at effectively 1.6K luma resolution in 2K mode, and chroma resolution maybe in the 1K range or a little higher. High-end 3-chip 1080p broadcast cameras are probably delivering something more like 1.8K for both luma and chroma. (Of course, if you're recording to HDCAM rather than HDCAM SR, you're only recording 1440 horizontal pixels, which would even things up a bit.)

 

As others have said, Red's 2K windowed mode is nothing to write home about. There's a reason they're really pushing for higher frame rates at full resolution with their next generation of cameras.

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